The waterproofing of footwear has received copious attention through the centuries, and many techniques have been proposed and used, tailored to the wide variety of footwear designs. Water-impermeable soles are common, as of rubber or plastic; and protective barriers of a variety of different types have been used for the shoe uppers—all directed to preventing the transfer of water from outside onto the uppers and/or into the inner part of the shoe that receives the foot. Uppers made of rubber or the like, as in work shoes or boots, moreover, do not allow the escape of the wearer's perspiration developed in the interior of the footwear and lead to undesired effects such as chafing, blister formation, growth of fungi and, at the very least, unpleasant odors.
Membranes have been developed such as “Gore-Tex”, described, for example, in German Patent 296D1932 (WO97/28711) and a similar membrane as described, for example, in U.S. Pat. No. 6,839,984, which provide the dual functionality of creating an effective water barrier while allowing some mitigation of internally developed water vapor, providing for the lowering of the internal production of perspiration, which, however, will still, none-the-less, accumulate within the footwear. Airflow through the upper has also been proposed as, for example described in English Patent 2,279,984, which will tend to decrease the partial pressure of the water vapor developed inside the shoe and thereby somewhat reduce liquid condensation in the footwear. Structures for achieving such airflow, and with it cooling, are loosely woven fabrics or mesh or apertures provided in the upper materials. Using such ventilated footwear in wet environments, however, allows water to enter and accumulate—often at a faster rate than water evaporation.
Other patent proposals for trying to solve such problems of inside and outside wetting effects are also described, for example, in German Patent 10328699.3 (WO2005/000061) and in U.S. Pat. Nos. 5,689,903 and 4,899,465 among others.
Similar splash-wetting action also occurs at the heel of the footwear as the wearer lifts it from the groundwater, splashing rearwardly upwardly to soil the heel region of the upper and the cuff regions of trousers or other long apparel extending thereto.
Up until the present invention, however, it is not believed that a universal structure for effectively shedding sole-adhered water spray has been achieved.